ORGANIZATION, BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)	3 Months Ended			6 Months Ended
	Jun. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) subsidiary	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of wholly-owned subsidiaries formed | subsidiary				2
Accumulated deficit	$ (590,843,000)			$ (590,843,000)		$ (575,425,000)
Cash and cash equivalents	7,410,000			7,410,000		$ 21,837,000
Revenue-supply agreement	$ 0	$ 8,000	$ 0	$ 8,000	$ 0